1. Field of the Invention
This invention relates to downhole drilling and more particularly to apparatus and methods for managing and discovering network topology in a downhole drilling environment.
2. Description of the Related Art
The ability to transmit data at high speeds along a drill string is a current goal and project of the downhole drilling industry. More and better information at the surface has the ability to significantly decrease drilling costs by enabling operators to more accurately direct the drill string to hydrocarbon deposits. Such information may also improve safety and reduce the environmental impacts of drilling. This technology may also be desirable to take advantage of numerous advances in the design of tools and techniques for oil and gas exploration, and may be used to provide real-time access to data such as temperature, pressure, inclination, salinity, and the like, while drilling.
In order to transmit data at high speeds along a drill string, various approaches have been suggested. Very few approaches, however, have achieved commercial implementation due to the high costs of development and constraints imposed by the downhole environment. One approach that is currently showing promise is to incorporate a “network” of data transmission cable and other communication equipment into the drill string. Due to the length of drill strings, which may exceed 20,000 feet, this may require placing network “nodes” at selected intervals along the drill string. These nodes may act as repeaters to amplify the data signal and to provide points of data collection along the drill string.
Nevertheless, implementing and maintaining a network in a downhole environment is a difficult task. Unlike many conventional networks, the topology of a downhole network may be in a constant state of flux. That is, the number and positioning of nodes, as well as the status of each of the nodes may change frequently in the network. For example, nodes may be added or removed from the network at the surface either one or several at a time. In other cases, breaks may occur in transmission lines or other transmission components that may cause particular nodes or groups of nodes to temporarily or permanently lose communication with the surface. In other cases, the nodes themselves may temporarily or permanently cease to function. These characteristics make it a challenge to discover, monitor, and manage network components in a downhole environment.
In view of the foregoing, what is needed is an apparatus and method for discovering, monitoring, and managing network components in a downhole environment. Ideally, such an apparatus and method would provide an up-to-date view of network topology, identify network components and their position within the network, and identify the operating status of the components. Further needed is an apparatus and method to detect changes to network topology frequently or in real time. Yet further needed is an apparatus and method to perform each of the above functions while minimizing traffic on the network.